There were spots of lighter color, where the leather had worn, some holes in the cloth inside (just above the woven waistband), and the woven cuffs have frayed.
seal brown" (after the sea mammal, not the special forces). But Waproo Dark Brown Raven Oil is a reasonable match for this. I purchased a 50 ml bottle from a shoe repair kiosk, and dyed the shoulder straps, collar, front pockets and front zip flap. There was was only half a bottle left, so I decided to order online a 500 ml bottle. It turned out I only needed about 150ml for the whole jacket. This is a powerful dye, so it is important to keep it off the cloth lining (and anything else you do not want dark brown).
The cuffs I repaired with a darning needle and dark brown DMC Stranded Cotton 3371.
The cloth lining was frayed just above the woven stretch cuff at the front bottom of the jacket, on each side, extending about 20 mm up. This is the point where my belt rubs on the inside of the jacket. I repaired it with a "fawn" iron-on patch (polyester cotton).
I cut the patch length-ways into four strips 23 mm wide. These I ironed onto the cloth lining inside each front side of the jacket, just above the stretch cuff. First I ironed one end of a strip to just next to the zipper, then stretched the jacket out, and kept it stretched while ironing the strip flat onto the fabric. When the patch cooled down I let go, and the fabric puckered around the stretch cuff. It took two overlapping strips to reach the side seam of the jacket. I did not patch the back of the jacket as there was no sign of wear.
The total cost was about $40, and should keep the coat looking good for a few more years.